package com.kk.springboot_001.mapper;

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.kk.springboot_001.pojo.User;
import org.apache.ibatis.annotations.*;

@Mapper
public interface UserMapper extends BaseMapper<User> {


    @Select("select user_id from tb_user where user_name=#{userName}")
    Integer getUserIdByUserName(String userName);
}
